Electrical connector and electrical terminals therefor



C. E. REYNOLDS Dec. 17, 1968 ELECTRICAL CONNECTOR AND ELECTRICAL TERMINALS THEREFOR 2 Sheets-Sheet 1 Filed June 20, 1967 INVENTOR. (mamas Euwpmo 'Rilnows Dec. 17, 1968 c. E. REYNOLDS ELECTRICAL CONNECTOR AND ELECTRICAL TERMINALS THEREFOR Filed June 20, 1967 2 Sheets-Sheet z United States Patent 17 Claims. (Cl. 339-17) ABSTRACT OF THE DISCLOSURE An electrical connector for connection to conductive means of a flexible cable means mounted on a panel having an opening provided with wall means along opposing sides and the flexible cable means being split and stripped at the opening to bear sections of the conductive means, the electrical connector comprises a dielectric housing having cavities extending therethrough corresponding to the number of conductive means, electrical contact members securely disposed in the cavities and including spring contact means projecting from at least one side of the housing for electrical engagement with respective bared sections of the conductive means when the housing is securely positioned within the opening thereby forcing the split flexible cable means against the wall means.

Cross reference to related application This application is a continuation-in-part of US. patent application Ser. No. 467,372, filed June 28, 1965, and now abandoned.

This invention relates to electrical connectors, and particularly to connectors of such construction that the connector contacts are individually removed and replaced, as desired. While the inventive concept is believed to be of a broad nature, it is particularly adaptable for use with flat-cable type conductors.

It is a primary objective of this invention to provide a new and improved electrical connector for flat conductors wherein the contact engaging end of each contact member comprises a springy conductive metal leaf that cannot become overstressed from excessive use or misuse.

Another object is to provide electrical contact members having contact engaging ends of springy conductive metal to bias against conductors of flat conductor cable.

Another objective is the provision of a connector housing with cavities therethrough to receive electrical contact members inserted therein.

Another objective is to provide latching means on the contact members to lock the members in place in housing cavities and limit their movement therein.

Another object is the provision of cavities in a housing to hold electrical contactors as well as allow their contact engaging ends to protrude so as to engage flat conductors.

Still another object is the provision of stabilizing electrical contact members in position in a connector housing for engagement with conductors of a flat cable.

A further object is the provision of the above connector which insertably mates with a suitable opening in a panel such that cable conductors are frictionally engaged between the connector and the panel.

These and other objects are achieved in a preferred embodiment of the invention in which the connector comprises an insulating block having a series of suitable cavities therethrough to receive contact members. Lead wires are suitably crimped to the contact members before their insertion into the block. Means are provided on the contact members to lock them in place in the cavities and 'ice prevent their over-insertion therein or accidental removal therefrom. The contact members can be withdrawn by utilizing a suitable tool. Contact engaging means are provided on the ends of the contact members including a spring portion lanced and formed from the floor thereof which protrudes from the block and biases against conductors when in use. The connector is latched into an opening in a panel such that the bare conductors of flat cable are frictionally engaged by the contact members to constitute electrical connections. The connector housing wedges the flat cable between its wall and a wall of the opening thereby mechanically holding the cable and at the same time relieving strain from the electrical connections.

In the drawings:

FIGURE 1 is a perspective exploded view of a connector in accordance with the present invention, a panel carrying flat cable and a contact member;

FIGURE 2 is a cross-sectional view taken through a connector and panel after termination and showing one contact member exploded therefrom;

FIGURE 3 is an enlarged plan view of a contact member;

FIGURE 4 is a longitudinal cross-sectional view of the contact member of FIGURE 3;

FIGURE 5 is a fragmentary cross-sectional view of latching means of the present connector; and

FIGURES 6-11 illustrate embodiments of the contact member with FIGURES 6, 8 and 10 being top plan views and FIGURES 7, 9 and 11 being cross-sectional views respectively thereof.

The latching means L and L on the connector housing is similar to that disclosed in U.S. Patent No. 2,891,103 which is assigned to the present assignee. The latching means includes stiffly flexible legs extending outwardly and integrally from respective ends of housing H. Latching surfaces LS extend outwardly from the latching legs, and the latching legs extend along respective ends of the housing toward the front thereof at an outward angular disposition with respect thereto. The surfaces from latching surfaces LS to the leading edges of the latching legs are tapered in order to facilitate camming the latching legs inwardly during insertion of the housing within an opening of a panel.

Referring now to the drawings and particularly FIG- URE 2, the present connector comprises a dielectric housing H suitably molded or formed in any conventional manner. Housing H has a series of spaced parallel cavities 2 formed therethrough to slidably receive contact members or terminals C. Each cavity 2 has a large opening 4 at its rearward end which receive a contact member C. Hole 6 extends from opening 4 into the cavity and provides an enclosure for the wire barrel W of contact member C. Hole 6 joins another hole 8 which is formed smaller by virture of a ledge 10. Hole 8 extends through housing H at opening 8 on the other end of the cavity. Ledge 10 provides a stop to limit forward longitudinal movement of a contact member C when the member is inserted into cavity 2. Approximately mid-way through hole 6 is a pair of undercuts 12 on opposite sidewalls of cavity 2. Undercuts 12 provide latching surfaces to be engaged by latching means on contact member C. This arrangement prevents accidental removal of the contact member from cavity 2, to be described later. The leftward end of housing H extend beyond opening 8' such that a floor surface 14 is planar and continuous from ledge 10. This provides a bearing surface for contact member C. Bearing surfaces 14 extending from all of cavities 2 are separated by longitudinal webs 16 which insulate one contact member C from the next where they protrude from housing H.

Referring now to FIGURES 3 and 4, contact member C is formed from a flat blank of electrically conductive metal such as brass or other suitable metal. One section of contact member C has a wire barrel W and insulation support barrel W in which a lead wire 18 is connected as by crimping. The other section of contact member C constitutes contact engaging means which engages a flatcable conductor F and carries electrical current from lead wire W through contact member C to cable conductor F. A projection 20 is formed downwardly from the floor of member C. Projection 20 abuts ledge 10 in cavity 2 and stops the forward insertion travel of member C within cavity 2. Spring lances 22 are formed outwardly from upstanding sidewalls 24 of member C. Ends 26 of lances 22 snap into undercuts 12 when member C is fully inserted into cavity 2. This arrangement constitutes the latching means which locks member C within cavity 2 and prevents its accidental Withdrawal therefrom.

A cantilever spring contact element 27' is formed upwardly from the floor area 21 of member C so that its free end 28 projects downwardly towards the floor area and wire barrel W. Semi-circular or hump-back section 30 of contact element 27 is ultimately biased against conductors F of flat cable, which biased engagement constitutes an electrical connection. End 28 has a coined and curled section 32 which has a wider transverse area than that of slot 34 located directly thereunder, FIGURE 4. Coined section 32 is pushed downwardly so as to move relative to slot 34 when the contact element is in use. This prevents overstressing of spring contact element 27 at point 36 where it projects upwardly from the floor of contact member C and provides a unique stop to prevent the free end of the contact element from moving beyond the plane of the floor of the contact member to maintain spring characteristics in the spring contact element to compensate for tolerances between the housing, contact members, opening in the panel and flat cable thickness. Sidewalls 24 serve to prevent the spring contact element from being moved outside the floor of the contact member.

Hump back section 30 on contact element 27 projects above sidewalls 25, FIGURE 4, so as to engage fiat conductors F when the connector means is in position. Section 30 can only be depressed to the distance equal to the height of sidewalls 25 under normal use. This provides a safety means whereby excessive pressure on spring contact element 27 will not bend or otherwise deform element 27.

It should be noted that spring contact element 27 is formed from the floor of contact member C. This allows the contact member to be preferably produced in end-toend continuous strip form with each member C joined to adjacent contact members by bridging straps S and S as illustrated by dotted lines in FIGURE 3. The contact members may also be produced in side-by-side continuous strip form; however, wider blank stock is needed to form the contact members, therefore, more stock is used.

In operation, contact members C are suitably crimped to the conductor and insulation portions of wires W to proivde a current coupling member for the connector. Contact members C are separately inserted and latched into cavities 2 of housing H. Flat cable F having a section of insulation removed from one side thereof is disposed over an opening in a panel P. Cable F is cut (dotted lines in FIGURE 1) so that one end of the connector may pass therethrough. Housing H with its contact members C in place is inserted into opening 0 in panel P. During insertion, the stripped ends of cable F fold inwardly into engagement with walls 38 of opening 0 and become wedged between housing H and these walls. At the same time, the extended ends of latching means L and L on housing H are cammed inwardly towards housing H via the tapered surfaces. When flanges 39 of the housing are bottomed against the walls of opening 0, latching means L and L' snap outwardly with latching surfaces LS engaging the rear surface of panel P to hold the connector in position on panel P. Thus, flanges 39 and latching means L, L maintain the housing in position within opening 0 of the panel. During insertion and when the connector is bottomed, as described above, section 30 of spring contact element 27 presses against conductors F of the cable to provide an electrical connection, FIGURE 4.

FIGURES 6 and 7 illustrate contact Ca which is an embodiment of contact C. Contact Ca is the same as contact C except that spring contact element 27a is anchored at 36a adjacent wire barrel We and spring cont-act elelIIICIlt 27a extends forwardly with free end 28a thereof being captured or disposed under lugs 40 which extend inwardly from sidewalls 25a and overlie floor 21a. Lugs 40 may be eliminated if desired.

FIGURES 8 and 9 illustrate contact Cb which is similar in every respect to contact Ca except that lugs 40b are disposed adjacent the anchored end of contact element 27b instead of the free end, and contact element 27b has a bend 41 therein below lugs 40b.

The reason that the spring contact elements 27a, 27b are anchored adjacent the wire barrel of contacts Ca, Cb is that such an arrangement increases the beam length of the contact elements, i.e., the point of engagement of the contact elements with a conductive element to be engaged therewith to the anchored end with respect to the embodiments of FIGURES 6-9 is a longer beam than the embodiment of FIGURES 3 and 4 in which the beam from the anchored end of the contact element to the point of contact is a shorter beam than those of FIGURES 6-9. Increasing the beam length of the spring contact elements decreases work-hardening of the anchored end, precludes the possible establishment of a permanent set which can easily occur in the spring contact element having a short beam and provides ease of engagement especially in the case of simultaneous engagement between multiple contacts as illustrated in FIGURE 1.

FIGURES 10 and 11 are directed to a further embodiment and they illustrate contact Cc which comprises spring contact element 270 that is stamped out of floor 21c and is anchored thereto at both ends. Slots 42 are disposed in floor 210 about midway of contact element 27c and sides 25c have formed therein inwardly-directed depressions 43 which have the inner ends thereof disposed between the areas defined by slots 42 and contact element 27c. Since slots 42 are present in floor 21c, floor 210 is formed into forward and rearward sections and formation of depressions 43 shortens the length of the contact thereby permitting spring contact element 270 to be formed so as to position a section thereof above the tops of sides 25c. Inwardly-directed depressions 43 act as springs to permit the forward end of the contact to move relative to the rear end during engagement of spring contact element 270 with a conductive element. This translates some of the spring characteristics of the spring contact element to spring depressions 43 thereby decreasing engagement forces between the spring contact element or elements and a conductive element or elements for engagement therewith as well as increasing the life of the spring contact element. The fact that the spring contact element is anchored at both ends protects this element and provides excellent reeling properties to place the contacts Cc in strip form on a reel for automatic termination application. Depressions 43 provide an automatic antioverstress feature to prevent spring contact element 270 from being overstressed. The additional spring elements 43 of the contact are divorced from the main current path of the spring contact element which prolongs the spring characteristics thereof. Contact Cc is a unique contact in that it provides a spring contact element or beam that is anchored at both ends to the forward and rearward sections of floor 21c, but it is free-floating under the influence of controlled spring means.

It will, therefore, be appreciated that the aforementioned and other desirable objects have been achieved; however, it should be emphasized that the particular embodiments of the invention, which are shown and described herein, are intended as merely illustrative and not as restrictive of the invention.

The invention is claimed in accordance with the following:

1. An electrical connector of generally U-shaped cross section including a contact portion having means integral with one end thereof for securing said connector to a conductor wire and contact means integral with the other end thereof for detachably engaging a flat conductor, said contact portion having laterally opposed sidewalls and a planar floor, said contact means including a spring element slotted from said planar floor and having a first end and a free end, said spring element directed upwardly to an apex from said planar floor and said first end and directed downwardly towards said floor at said free end, said apex extending above said sidewalls, said free end adapted to move relative to said planar floor upon pressure being applied to said apex, the slot from which said spring element is formed having a section of reduced width thereby forming a section of reduced cross section in said spring element between said apex and said free end, said free end being disposed opposite said section of reduced width to prevent said free end from passing through said slot.

2. An electrical connector according to claim 1 wherein said planar floor has a downward projection adapted to abut a ledge in an associate housing means to limit forward travel of said connector in said housing means, latching means on said sidewalls including spring lances biased outwardly from said sidewalls and adapted to snap into undercuts in said housing means to prevent accidental withdrawal of said connector from said housing means.

3. An electrical connector according to claim 1 wherein said planar floor and said sidewalls constitute a stop to prevent said free end of said spring element from moving laterally beyond said planar floor.

4. An electrical connector according to claim 1 wherein said sidewalls constitute a stop to receive excessive pressure imposed on said apex of said spring element.

5. An electrical connection comprising a panel having an opening provided with inwardly-directed walls along opposite sides thereof, flexible cable means disposed on said panel over said opening, said flexible cable means being split and stripped at said opening thereby exposing conductor means, electrical connector means including a dielectric housing having electrical connector means disposed therein, said electrical connector means having spring contact means extending from opposing side sections of said dielectric housing, said dielectric housing having a portion including said opposing side sections disposed in said opening with said spring contact means in electrical engagement with corresponding ones of said conductor means thereby directing split sections of said flexible cable means against respective walls, and holding means on said housing in engagement with said panel thereby maintaining said housing in place on said panel.

6. An electrical connector for connection to conductive means of a flexible cable means mounted on a panel with said panel having an opening provided with Wall means along opposing sides and said flexible cable means being split and stripped at said opening to bare sections of said conductive means, said electrical connector comprising a dielectric housing having cavities extending therethrough corresponding to the number of said conductive means, electrical contact members disposed in said cavities, means on said electrical contact members and in said cavities securing said electrical contact members in position in said cavities, said electrical contact members including spring contact means projecting from at least one side of said housing for electrical engagement with respective bared sections of said conductive means when said housing is inserted within said opening thereby forcing said split flexible cable means against said wall means, and securing means on said housing to secure said housing in position on said panel.

7. An electrical connector according to claim 6 wherein said securing means comprise stiffly flexible arm means extending outwardly from said housing at opposite ends and extending toward an insertion end of said housing for resilient engagement with other opposing sides of said opening.

8. An electrical connector according to claim 6 wherein said housing includes flange means to limit movement of said housing within said opening.

9. An electrical connector comprising a contact section and a conductor-engaging section, said contact section having a substantially planar floor and a spring contact member slotted from said planar floor, said spring contact member having one end connected to said planar floor and a free end, said spring contact member extending upwardly from said planar floor at said one end to an apex and extending downwardly from said apex towards said planar floor with said free end being movable relative to said planar floor upon pressure being applied to said spring contact member, the slot from which said spring contact member is formed having a section of reduced width thereby forming a section in said spring contact member of reduced cross section, said free end being disposed opposite said section of reduced width to prevent said free end from passing through said slot.

10. An electrical connector according to claim 9 wherein said one end of said spring contact member is conneted to said planar floor adjacent a front end of said planar floor with said free end being disposed adjacent said conductor-engaging section.

11. An electrical connector according to claim 9 wherein said one end of said spring contact member is connected to said planar floor adjacent said conductor-engaging section with said free end being disposed adjacent a front end of said planar floor.

12. An electrical connector according to claim 9 wherein side wall means extend outwardly from said planar floor on each side of said spring contact member and lug means extending outwardly from said side wall means in alignment with said free end so that said free end is disposed between said lug means and said planar floor.

13. An electrical connector according to claim 9 wherein side wall means extend outwardly from said planar floor on each side of said spring contact member and lug means extending outwardly from said side wall means and in engagement with a section of said spring contact member proximate said one end.

14. An electrical connector comprising a contact section having a planar floor, a spring contact member slotted from said planar floor and having both ends connected thereto, said floor having slots disposed about midway of said spring contact member, side walls extending outwardly from said floor on each side of said spring contact member, and spring means provided in said side walls in alignment with said slots for decreasing the engagement forces in said spring contact member.

15. An electrical connector according to claim 14 wherein said spring means define inwardly-directed depressions in said side walls that extend inwardly toward each other and are disposed under said spring contact member.

16. An electrical connector comprising a conductor-engaging section and a contact section, said conductor-engaging section having means for electrically connecting same to an electrical conductor, said contact section having a planar floor provided with substantially parallel longitudinal slots from which a section of said floor has been pushed outwardly from said floor defining a spring contact member, said planar floor having additional slots thereby dividing said floor into a forward section and a rearward section with each end of said spring contact member being connected to a respective one of said forward section and rearward section so that these sections are movable with respect to each other when force is applied to said spring contact member, and spring means connecting said forward and rearward sections together.

17. An electrical connector according to claim 16 wherein said spring means comprise side wall means extending outwardly from said floor on each side of said spring contact member and inwardly-directed depressions disposed in said side wall means under said spring contact member.

References Cited UNITED STATES PATENTS 2,738,485 3/1956 Batcheller 339-258 3,163,484 12/1964 Herman et al 339-258 3,365,694 1/1968 Parker 339-17 MARVIN A. CHAMPION, Primary Examiner.

JOSEPH H. MCGLYNN, Assistant Examiner.

US. Cl. X.R. 33991, 256, 258 

